Erroneous results may arise when users, operating remote computers running network-based applications, submit the same request transmission to a host computer multiple times. This often happens when a client operating a remote computer running a web-based application, submits requests to Internet servers. Long response times by the Internet server, due to network delays or other performance issues, encourage clients to make such multiple, redundant submissions. Examples where redundant request transmission are often submitted to Internet-based servers are operations that comprise editing data structures, submitting payments, or other incremental changes to an object.
Merchants and other providers and are increasingly operating web-based platforms on Internet servers to sell goods, execute financial-instrument trades, and conduct other transactions. A common platform is one that allows a client to place goods in a virtual “shopping cart”. Then, when the client is prepared to finalize the purchase, he proceeds to a virtual “checkout”. At this stage, all items in the client's shopping cart and total amount due are displayed along with the client's credit card or other payment information. The client then clicks on a “submit”, “pay”, or “buy” button displayed on the web page thereby executing the transaction to purchase the goods.
If precautions are not taken, the client's order may be inadvertently submitted twice. For example, if the client clicks the submit button, then reloads the page, the information may be re-submitted, causing the order to be entered twice. Or, if the client does not receive a confirmation of the purchase in a timely manner, he may hit the “pay” button again in frustration, thereby executing a duplicate purchase. Such redundant transmissions result in great inconvenience to the client, who has to return the unwanted goods and seek a refund for the duplicate order. The problem is sufficiently common that payment services frequently warn clients against pressing the ‘Pay’ button twice, since this may result in multiple payment transactions being performed by the server and client over billing.
What is needed are systems, methods, and software for preventing computers from processing redundant client transmissions sent from remote computers. Such systems, methods, and software would benefit clients, online merchants, and traders by, among other things, preventing unintended duplicate orders.